Currently, there is a trend toward having various electronic products slimmer and slimmer. To go with the trend, the electronic components, such as the semiconductor components, of the electronic products need to be considerably miniaturized. This leads to a problem of heat dissipation, which seriously affects the performance of the electronic equipments and systems.
To speak more specifically, the miniaturization of the semiconductor components results in increase of heat flux. The increase of heat flux challenges the cooling of an electronic product more than pure increase of total heat. This is because the increase of heat flux will lead to overheating at different times by different lengths and may cause malfunction of the electronic product.
A conventional vapor chamber (VC) heat spreader is disposed on a chip to serve as a heat sink. The vapor chamber heat spreader has an upper wall and a lower wall and a capillary wick structure sandwiched therebetween. The capillary wick structure has capillary copper coating or sintered copper pillars or blisters for supporting the upper and lower walls to form the backflow paths. However, the upper and lower walls of the vapor chamber heat spreader have a very thin thickness (under 1.5 mm). When applying the capillary wick structure to a micro heat spreader for supporting the upper and lower walls thereof, only those sections at the sintered copper pillars or blisters are supported. Under such circumstance, the remaining sections are likely to collapse or sink. As a result, the planarity and strength of the micro heat spreader will be deteriorated. In this case, it is hard to slim the micro heat spreader.
Moreover, it is critical to select a suitable wick structure for the vapor chamber heat spreader. The wick structure must be able to keep the flow speed of the condensed liquid and have sufficient capillary force to overcome gravity. According to the aforesaid, the conventional vapor chamber heat spreader has the following defects:
1. The conventional vapor chamber heat spreader is too thick.
2. The conventional vapor chamber heat spreader can be hardly slimmed.